Korg Polysix

I've owned a Korg Polysix for some many years, and I've often had the lid open for one reason or another, not least curiousity. This page includes some details of two major parts of the voice circuitry, redrawn for clarity. The full service manual with schematics for the Polysix is available online at Old Crow's Synth Shop, which has excellent Polysix pages.

Korg PolySix Oscillator

The Korg Polysix oscillator is interesting as it is a linear (V/Hz) oscillator, rather than the more common exponential (V/Oct) type. When the Poly6 was reinvented as the Poly61 with MIDI and digital parameter access instead of knobs, it also lost its real VCOs for DCOs.

Korg PolySix SSM2044 Filter

Korg apparently used the SSM 2044 in many synths. I'd be interested to know how much the various designs vary, if at all. The Polysix is quite an interesting case, as it runs the chip on +/-5V. This probably entails some of the other component changes. The Poly6 only has a single oscillator, so it uses the second input to cancel any DC offset on the output.

Korg managed to squeeze the whole voice onto a small area of PCB. The six voices only occupy less than half a single board inside the synth.

credits & legal

All design and development by Tom Wiltshire. All code and content copyright Tom Wiltshire 2006-2008 for Electric Druid. Contact

Please note that whilst I've got no problem with people using and modifying my code or circuits for their own use or education, the information on these pages is copyright, and not for commercial use. If you'd like to discuss commercial use of my work, please contact me.